Luminaire



D. E. WELTY May 10, 1966 LUMINAIRE 2 Sheets-Sheet 1 Filed Sept. L7, 1963HINVENTOR. J

ATTORNEYS D. E. WELTY May 10, 1966 LUMINAIRE 2 Sheets-Sheet 2 FiledSept. 17, 1963 INVENTOR. D455 W51 ry ATTORNEYS United States PatentDelaware Filed Sept. 17, 1963, Ser. No. 309,432

Claims. (Cl. 240-93) The present invention relates to luminaires and isconcerned with a refractor for use with a reflector element to provideimproved distribution of reflected light. More particularly, theinvention relates to a shallow refractor designed to modify thedistribution from a light source, such as a one thousand watt mercuryfloodlighting reflector, to produce a narrow uniform light distributionpattern.

The invention results in improved light distribution by eliminatingsecondary peaks which, in prior art luminaires, are locatedapproximately thirty to forty degrees laterally from the main beam axisand twenty degrees vertically below the main beam axis. By utilizing therefractor of the invention, which employs discrete prismatic panelscorresponding to similarly discrete reflector panels, the light from thereflector is uncrossed. The normally crossed light from the reflector,which would ordinarily produce secondary peaks of light adjacent themain beam, is utilized by blending it into the main beam, therebypresenting a more uniformly distributed beam of light emanating from theluminaire.

Accordingly, an object of the present invention is to provide animproved luminaire refractor.

Another object of the invention is to provide a novel combination of afloodlighting reflector and refractor for achieving uniform distributionof the transmitted light.

A further object of this invention is to provide a novel multi-panelledrefractor, in combination with a rnulti-panelled reflector.

Further objects and advantages of the invention will become apparent andthe invention will be fully understood from the following descriptionand drawings in which:

FIG. 1 is an end view of a luminaire, with a portion of the refractorbroken away;

FIG. 2 is a cross-section taken along line 22 of FIG. 1;

FIG. 3 is a cross-section taken along line 3-3 of FIG. 1;

FIG. 4 is a graph showing the lateral distribution through the plane ofthe main beam of the reflector alone (dotted lines) and thereflector-refractor combination (solid line); and

FIG. 5 is a graph showing the vertical distribution through the plane ofthe main beam of the reflector alone (dotted lines) and thereflector-refractor combination (solid line).

In the drawings, the luminaire is designated in general by the numeral10. A reflector 12 is formed as a plurality of discrete parabolicpanels, the outer sides and ends of which form a generally oval shapedflanged mouth 14. The reflector is illustrated having longitudinal andtransverse axes 15 and 17, respectively. A light source 36, such as aone thousand watt mercury lamp, is mounted horizontally along transverseaxis 17 of the reflector 12.

Rear panel 16 of the reflector is positioned behind the light source 36.This panel reflects light into a sharp main beam essentiallyperpendicular to the axes of the luminaire. This beam is showngraphically at M in FIGS. 4 and 5. Typical ray paths from panel 16 areillustrated diagrammatically at 20, 22, 24, and 26 of FIG. 2, and at 28,30, 32 and 34 of FIG. 3.

3,250,913 Patented May 10, 1966 Reflector panels 38 and 40 arerelatively large parabolic sections comprising the two sides ofreflector 12, and diverge outwardly from the edges of rear panel 16 tothe flanged mouth 14 of the reflector. The light striking the centralportions 37 of reflector panels 38 and 40 is reflected at approximatelythirty to forty degrees laterally (see FIG. 3) across a center planethrough the longitudinal axis of the reflector, i.e. across the axis ofthe main beam M, and provides the major portion of light which makes upthe secondary peaks 42 as shown in FIG. 4. Reflected light from theupper and lower portions of panels 38 and 40 adds to the secondarypeaks. Light striking the top portion 39 of panels 38 and 40v is alsoreflected at approximately thirty to forty degrees laterally across theaxis of the main beam, and downwardly to approximately twenty-fivedegrees below a center plane through the horizontal or short axis of theluminaire. Light striking the bottom portion 41 of panels 38 and 40 isreflected at thirty to forth degrees laterally and upwardly toapproximately twenty-five above the horizontal axis. The diagrammaticalillustrations of the light rays emanating from source 36 and reflectedby panels 38 and 40 are indicated by paths 43, 44, 46 and 48, 50, 52 inFIG. 3.

Reflector panel 56 is a parabolic section comprising the top ofreflector 12. Light striking panel 56 is reflected downwardly atapproximately twenty degrees below the main beam. Light from thisreflected beam is shown as creating the secondary peak 58 in FIG. 5. InFIG. 2 there is shown diagrammatically, ray paths of light whichoriginate from source 36 and are reflected by panel 36. The rays arenumbered 60, 62 and 64.

Reflector panel 66 is a comparatively small V-shaped parabolic sectioncomprising the bottom of the reflector. The light reflected by thispanel is directed generally into the main beam of light.

Thus it can be understood that reflector panel 16 forms the main beam oflight transmitted by the reflector and the side panels 38 and 40 and thetop panel 56 reflect their incident light across the main beam axis toform what is essentially a hollow cone of light around the beam. Thishollow cone of light is utilized by the refractor of the invention bybringing it into the main beam.

A refractor 68 in accordance with the invention is designed to uncrossthe hollow cone of light from reflector panels 38, 40 and 56 in amountsjust sufficient to bring the light distribution of each of these panelsad jacent the edge of the main beam distribution. Consequently, thesecondary peaks in the distribution curves produced by the reflectorpanels 38, 40 and 56 are effeotively blended into the main beam as shownin FIGS. 4 and 5 in the solid line light distribution curves.

The refractor 68 is fitted into the flanged opening of the reflector andis conventionally seated upon a ring 69 for cushioning the reflector andrefractor elements. Refractor 68 comprises a plurality of discreteprismatic panels 72, 74, 76 and 78 surrounding a central difluser panel70. i

Panel 70 contains a plurality of shallow diffusing flutes which receivethe main beam of reflected light from reflector panel 16. Panel 70 doesnot change the distribution of the reflected main beam, as shown by thediagrammatical illustration of the paths of rays emanating from source36 and reflected by panel 16 outwardly to panel 70. Thus, ray paths 20,22, 23 and 24, 26, 27 of-FIG. 2 and paths 28, 30, 31 and 32, 34, 35 ofFIG. 3 show the light beams emerging from the luminaire in a straightcourse to comprise the main beam of light.

Refractor panel 72 is positioned between panels 74 and adjacent panel 70at the flattened top end of the s refractor. Panel 72 includes aplurality of elevating prisms which refract the light reflected frompanel 56 upwardly to the bottom edge of the main beam of light. Thealteration of the vertical distribution due to the refraction of thelight reflecting from panel 56 is shown on the curve in FIG. 5, wherethe dotted lines indicate the light pattern without the refractor andthe solid lines with the refractor. Typical ray paths for the refractedlight are shown in FIG. 2 as 60, 62 and 63. It will be noted that thebeam of light represented by 60, 62 and 64 has been refracted outwardlyto a path which now approximately parallels the main beam of light. Wereit not for refractor panel 72 the portion of light reflected from panel56 would cross the main beam and result in a secondary peak 58.

Panels 74 consisting of two similar sections are located adjacent panel'72, one section on each side thereof, and having a side adjacent panels76. Panels 74 receive the light that is reflected from the top portion39 of panels 38 and 4t Panels 74 serve to refract the light laterallyand upwardly toward the luminaire axes to the edge of the main beam. Theprisms comprising panels 74 are set on diagonal paths to thereby provideboth lateral and vertical prismatic action.

Refractor panels 76 receive the light reflected from the central portion37 of reflector panels 33 and 40 and refract the light laterally towardthe main beam axis to the edge of the main beam. Panels 76 consist oftwo similar sections positioned one on each side of panel 70 andadjacent a section of panels 74 and 78. The change resulting from theaforesaid lateral distribution of that portion of the light enteringpanels 76 is shown in FIG. 4. FIG. 3 depicts the ray paths of the lightrefracted through panel 76, designated as 43, 44, 45 and 48, 50, 51.Thus, the rays have been refracted from their original paths by anamount equal to the angle between 45 and 46 or 51 and 52.

Refractor panels 78 include two similar sections positioned adjacenteach other at the pointed end of refractor 68. Panel 78 receives thelight from the lower portion of reflector panels 38 and 40 and refractthis light laterally and downwardly toward the beam axes to the edge ofthe main beam. The prisms in panels 78 are set on diagonal paths toprovide both lateral and vertical prismatic action.

Thus the design of the refractor of this invention provides for arealignment of certain portions of the light emanating from the lightsource and reflected from the reflector panel to there-by present a beamor cone of light from the luminaire which has a relatively smoothdistribution. The results are achieved by eliminating the secondarypeaks located approximately thirty to forty degrees laterally from themain beam axis and twenty degrees vertically below the main beam axis.The refractor 68 passes a main beam of light along a path consistentwith its original direction and refracts the portions of the lightincident upon the reflector side and top panels 38, 40 and 56. Therefracted portions of the light are so directed as to fall along theedges of the main beam to thereby provide the relatively smooth totallight distribution achieved in this invention.

It will be understood that the reflector-refractor panel arrangementdisclosed herein may be adjusted to provide for any light distributionpattern which may be desired. Many variations and modifications of theparticular arrangement herein illustrated will be apparent to thoseskilled in the art, and therefore, the invention is not to be construedas limited except as defined in the following claims.

What is claimed is:

1. In a luminaire having a generally hemispherical multi-panelledreflector, said reflector having an oval shaped opening extending alonga longitudinal axis from one end of the luminaire to the other, and alight source positioned within said reflector, said reflector and lightsource combining to produce a main beam of reflected light outwardlyalong an extended center line and a substantially hollow cone ofreflected light around the main beam, the improvement comprising amultipanelled shallow glass refractor connected to the reflectoradjacent the oval shaped opening thereof, said multi-panelled shallowglass refractor including a centrally positioned first panel having aplurality of shallow diffusing flutes, a second panel positionedadjacent said first panel and toward said one end of said luminaire andhaving a plurality of prism means for directing reflected light incidentthereon away from said center line toward said one end of the luminaire,third and fourth similarly shaped panels positioned one on each side ofsaid second panel and having prism means set on diagonal paths, fordirecting reflected light incident thereon laterally away from saidlongitudinal axis and from said center line toward said one end of theluminaire, fifth and sixth similarly shaped laterally directing lightpanels positioned one on each side of said first panel and adjacent saidthird and fourth panels respectively, and seventh and eighth similarlyshaped panels positioned adjacent each other and said first panel eachhaving a side positioned adjacent said fifth and sixth panelsrespectively and having prism means for redirecting reflected lightincident thereon laterally away from said longitudinal axis and fromsaid center line toward said other end of said luminaire whereby saidrefractor passes the main beam of reflected light in its originaldirection from said reflector and refracts the remaining light formingthe cone of reflected light in such directions that said cone of lightfalls along the edges of the beam to provide a relatively smoothdistribution of the total light emanating from the light source.

2. A luminaire, comprising a generally hemispherical reflector having anopen end therein, a light source positioned within said reflector, saidreflector including a plurality of reflector panels 'which redirectlight emanating from said light source into a main beam of light and asubstantially hollow cone of light around the main beam, a refractorconnected to the reflector across the open end thereof, said refractorincluding a plurality of refractor panels and a diffuser panel, saiddiffuser panel including means for transmitting the main beam withoutchanging the distribution thereof, and said refractor panels includingmeans for redistributing the cone of light reflected from said reflectorpanels into the main beam of light and thereby provide a more uniformlydistributed luminaire light output.

3. A luminaire comprising a reflector, a light source positioned withinthe reflector, said reflector including means for intercepting lightfrom the source and for directing the same into a main beam, saidreflector further including means for directing some of said light intoa hollow cone surrounding said main beam, a refractor positionedforwardly of said light source and said reflector and including meansfor transmitting substantially unaltered the light from the reflectorwhich is directed into the main beam, said refractor additionallyincluding means for redirecting the light from the reflector which isdirected into the hollow cone surrounding the main beam into the mainbeam.

4. The luminaire of claim 3, wherein said means included in saidreflector for directing some of the light into a hollow cone comprisesreflector surfaces constituting means for directing said some of thelight inwardly across the axis of the main beam and outwardly of theluminaire for forming the hollow cone of light surrounding said mainbeam, and said means for redirecting light comprise prisms, the surfacesof which constitute means for receiving said'some of said light beforeit crosses the main beam axis, and for directing the same laterally awayfrom the main beam axis.

5. A refractor comprising means for receiving and transmitting a mainbeam of reflected light generally centrally of the refractor along anextended center line and for simultaneously receiving and refracting acone of reflected light extending substantially along the center line ofthe main beam and around the main beam, said means including a pluralityof sections of light transmitting elements, said sections including acentermost section, said elements of which centermost section includemeans for diflusing the main beam of light without afiecting the generaldirection thereof, said sections including sections surrounding saidcentermos-t of said sections, said surrounding sections including meansfor redirecting the reflected hollow cone of light incident ReferencesCited by the Examiner UNITED STATES PATENTS OTHER REFERENCES Jolley,William, and Wilson: Theory and Design of 10 Illuminating EngineeringEquipment, John Wiley &

Sons, 1931, pages 297-317.

NORTON ANSHER, Primary Examiner.

thereon laterally of the center line into and in the di- 1 CHARLESRHODES, Assistant Examiner I rection of the main beam.

5. A REFRACTOR COMPRISING MEANS FOR RECEIVING AND TRANSMITTING A MAINBEAM OF REFLECTED LIGHT GENERALLY CENTRALLY OF THE REFRACTOR ALONG ANEXTENDED CENTER LINE AND FOR SIMULTANEOUSLY RECEIVING AND REFRACTING ACONE OF REFLECTED LIGHT EXTENDING SUBSTANTIALLY ALONG THE CENTER LINE OFTHE MAIN BEAM AND AROUND THE MAIN BEAM, SAID MEANS INCLUDING A PLURALITYOF SECTIONS OF LIGHT TRANSMITTING ELEMENTS, SAID SECTIONS INCLUDING ACENTERMOST SECTION, SAID ELEMENTS OF WHICH CENTERMOST SECTION IN-